Here is the source code for the HEPTopTagger as developed in
(Heidelberg-Eugene-Paris Top Tagger)
The version of the tagger we provide here was experimentally validated in
JHEP 1606 (2016) 093
An extended version using a variable R approach and by combining the HEPTopTagger with other tagging approaches using a Boosted-Decision-Tree is available here. We provide the core of the HEPTopTagger here separately because many users prefer to include an implementation of the tagger with little overheads.
Our source code comes with an example and instructions how to include the tagger in your analysis code.